Flash memory is non-volatile, which means that it does not need power to maintain the information stored in the chip. Flash memory is a technology that is primarily used in memory cards, and USB flash drives (thumb drives, handy drive, memory stick, flash stick, jump drive) for general storage and transfer of data between computers and other digital products. Examples of applications include PDAs and laptop computers, digital audio players, digital cameras and mobile phones. It has also gained some popularity in the game console market. In addition, flash memory offers read access times and better kinetic shock resistance than hard disks.
Conventional flash memory products employ floating gate technologies, that is, gates that are completely surrounded by an insulating layer, such as silicon oxide. The presence or absence of charge in the floating gates represents binary information. With aggressive scaling of flash devices, disadvantages in the interaction of adjacent floating gates becomes apparent, which typically causes an undesirable threshold voltage (Vt) shift.